The Replenishment Flow: When to Remind a Customer to Reorder

You're almost out of something you reorder. The protein powder, the dog food, whatever it is. And right then, an email lands. "Running low?" One tap, it's on the way. 

You don't shop around. Why would you? They caught you at the exact moment you needed them.

That's a replenishment flow. It's one of the most quietly profitable things a consumable brand can build, and most never do.

What a replenishment flow is

A replenishment flow is a Klaviyo flow that reminds a customer to reorder a product right before they run out. You estimate how long the product lasts, and the email lands while they still have a little left and reordering is on their mind.

The timing is the offer. You're not running a sale or twisting an arm. You're showing up at the one moment the reminder is genuinely useful. It usually lives alongside your post-purchase flow, but it's worth building deliberately, not leaving as an afterthought.

Is your catalog right for it?

Replenishment, in the strict sense, works for products people use up and rebuy on a rhythm. Coffee, supplements, skincare, pet food, candles, razor blades. Things that run out.

If you sell one-and-done products, you don't replenish them. Nobody reorders the couch they just bought. But plenty of furniture and home brands miss easy revenue here, because the same instinct still applies, just aimed at different products.

Take that couch. The customer won't buy another one next month, but they just walked into a set of natural next purchases. The throw pillows and the rug that finish the room. A fabric care kit and cleaner. The protection plan or extended warranty. The matching ottoman. You time those for the moment they own the couch and want to complete the look, the same way you'd time a refill for the moment someone runs low.

So whether or not you sell consumables, the question is the same. After someone buys, what will they predictably want next, and when? Refills of the same product run on a replenishment flow. Complementary products are cross-sell, and that work lives in your post-purchase flow. This post is about the first kind, so if your catalog has anything that runs out, keep reading.

Getting the timing right

Everything in this flow rides on one decision: when the email goes out.

Send too early and they still have plenty, so the reminder feels pushy. Send too late and they've already run out, maybe bought a replacement somewhere else. The window you want is short: low, but not empty.

How do you find it? Start with what you know. If a bag of coffee lasts about three weeks, the reminder goes out around day 18 to 20. A 30-day supplement gets one around day 25. Get it close, then adjust from there.

If you genuinely don't know how long your product lasts, your purchase data does. Look at how many days typically pass between a repeat customer's orders of the same product. That gap is your timing. Set the flow a few days ahead of it.

Different products, different clocks

Here's where brands slip. They build one replenishment reminder and fire it at everyone on the same schedule.

A moisturizer and a cleanser from the same line don't run out at the same rate. Neither do a small bag of coffee and a large one. If you sell more than one consumable, the flow should branch by product, so each reminder matches how long that specific thing actually lasts.

That's more work up front. Skip it, and the reminders are a week off for half your products.

What the email actually does

Keep it simple. The best replenishment email barely sells, because the timing already did the selling.

It says: you're probably running low. Here's the thing you bought. Reorder in one tap. That's most of it.

A few additions that help when they fit:

• A direct reorder link that drops the exact product back in their cart. Every step you remove is a sale you keep.

• A subscribe option. Someone reordering the same thing on a rhythm is a perfect candidate for subscribe-and-save, and this email is the natural place to offer it.

• A light, real reason to act. Free shipping over a threshold, or a bundle that saves them money. Skip the fake urgency. They already need the product.

Don't remind someone who already reordered

One rule matters more than it sounds. If a customer already reordered, or they're on a subscription, the flow has to know and stop.

Nothing undoes the goodwill of a well-timed reminder faster than getting one for something you bought last week. Build that exit in from the start: if they buy that product again, they drop out of the flow.

Before you build it

• Do you sell anything people use up and buy again on a rhythm? (If no, skip this flow.)

• Do you know, roughly, how long each consumable lasts? (If not, pull the gap between repeat orders in your data.)

• Does the flow branch by product, or fire one generic reminder at everyone?

• Is there a one-tap reorder link in the email?

• Are you offering subscribe-and-save to the people clearly buying on a cycle?

• Does the flow stop for anyone who already reordered or subscribed?

A well-built replenishment flow is one of the highest-return things a consumable brand can run, and it's usually sitting unbuilt. Earning that reorder is a big part of why a repeat customer is worth more than a new one.

If you sell something people reorder and you're not catching them at the right moment, that's worth fixing. Book a free call and we'll talk through your catalog and whether a replenishment flow makes sense for your brand. No pressure, no pitch.

Email is a system, not a send.

— Alex

Need help implementing these strategies in your email marketing program?

Frequently asked questions

What is a replenishment flow in Klaviyo?

It's an automated Klaviyo flow that reminds a customer to reorder a consumable product right before they run out. You estimate how long the product lasts and time the email to land while they still have a little left, when reordering is genuinely useful.

When should a replenishment email be sent?

Send it in the short window when the customer is low but not empty. If a product lasts about a month, the reminder goes out a few days before the month is up. If you're not sure of the window, look at the typical gap between a repeat customer's orders of that product and send a few days ahead of it.

Which products need a replenishment flow?

Consumables that people use up and rebuy on a rhythm: coffee, supplements, skincare, pet food, and the like. Products people buy once, like furniture or electronics, don't need one, though they can still use a cross-sell follow-up for complementary products.

What's the difference between a replenishment flow and subscribe-and-save?

A replenishment flow reminds someone to come back and reorder by hand each time. Subscribe-and-save sets the reorder to happen automatically. They work together: the replenishment email is the natural place to offer the subscription to someone clearly buying on a cycle.